>Since my calculus students will have graphers, is it the>consensus that I should stop teaching my precalculus>students such tricks to aide graphing as shifting & stretching>functions and symmetry? I'd love to stop teaching this, because it>would free time for other "essential" topics, which I do not>get to.>>Bill Larson>Geneva

We should still teach the concepts but maybe with the aid of the graphingcalculator.

That is, given y=a+b*f(c*x+d), kids still need to know that varying a, b, c,and d cause predictable changes in the graph of f.